Installation for mechanically recording sound on endless tapes coated with wax



F b-" 1942- H. WESTERKAMP 73 INSTALLATION FOR MECHANICALLY RECORDING SOUND ON ENDLESS TAPES COATED WITH WAX Filed July 8., 1959 fnVen/on:

Patented Feb. 24, 1942 INSTALLATION CORDING SOUND N COATED WITH WAX Hugo Westerkamp, Cologne-Braunsfeld, Germany Application 1 Claim. The invention relates to the mechanical recording of sound an endless tapes coated with wax. The sound tapes, which consist of a carrier of tape form and a thin layer of wax composition particularly suitable for sound recording uniformly applied thereto, are passed through a sound-recording apparatus having a stylus for cutting sound tracks into the layer of wax.

The layer of wax must not come into contact with any other objects, particularly after the sound track has been cut therein, since the slightest additional deformation of the layer'of wax impairs the sound recording. Quite apart from this, the sound tape must be withheld from any external influences, because the wax layer is inclined to crack off from its carrier readily and if only one fragment of the wax layer is cracked off the entire record tape is rendered useless. The difliculty in handling the sound tape during the recording is further increased by the fact that sound tapes are. generally of veryv great length, which may amount to 100 m. and more in the case of lengthy sound recordings. 7 e In, the production of mechanical sound records on unwax'ed tapes, for example on tapes provided with a layer of gelatine, the endless tape lies as a roll with a drawn-out loop on a.

FOR MECHANICALLY nu- ENDLESS TAPES July 8,1939, sci-n1 No. 283,489 Germany August 13, 1938 power-driven or friction-driven plate. It has;

been iound impossible to arrange waxed sound tapes in the same or a similar manner in the sound-recording apparatus for the reasons'menthe wax layer of the sound tape and the carrier of tape is'unavoidable, not only at the entrance of the tape into the roll, but also in the roll itself.

In order to overcome the sound tape, it is proposed in accordance with the invention to pass the endless sound tape out- .tioned in the foregoing, since friction between this difllculty in handling side the'sound recording apparatus in loops about a plurality of tension rollers and ifdesired, to

twist it through 180 between the sound-record-q "ing point and the'tension rollers adjacent thereto."

The tension rollers and that part of the sound tape extending outside the sound-recording apparatus are preferably enclosed in a heatable chamber, the heat of which brings the wax composition of the sound tape to a degree of "softness which is desirable for the sound recording.

The drawing shows dlagrammaticallytwo .constructional examples of an installationv for recording sound according to the invention,

In Figure 1, I, is the sound-recording apparatus with the roller 2 over which the tape passes during the cutting 'of'the sound traclr by the stylus 3. The sound tape, which consists of the carrier! of tape form and the wax layer 5, passes inside the recording apparatus only as far as is essential. The entire remaining part of the sound tape extends out of the recording apparatus and passes over a tension roller 5, the tension exerted by which is adjustable by means of the spring Land the adjustment screw 8 and which is secured pivotally to a slide 9 for the purpose of adaptation to the momentary length of the sounditape, the said slide being adapted to be displaced and held fast on a guide In.

In the installation shown in Figure 2, a plurality of tension rollers H, l2, l3, l4 and ii are 'provided which are also adjustable for the 'pur- 25 for supporting the tension rollers l2, I4, and

being connected by springs 28 to the threaded members 21 which may be adjusted in position by the wing .nuts 28 whereby to vary the tensional pull exerted through the levers 25 upon the successive flights of the tape. The sound tape, which passes from the sound-recording point to the tension roller Ii situated outside the recording apparatus, has at l6 a turning point in order that the carrier, and not the engraveable wax layer upon it, may come into contact with the surface of the tension roller I I. Corresponding turning points of the sound tape are provided at. "between the tension rollers ll and I2, at l8 between the clamping rollers i2 and I3 and at I9 between the clamping rollers i3 and it, which are all situated outside the recording apparatus. From the tension roller ,the soundtape passes, without turning, over the tension roller l5 and back to the so'und-recording point, The arrangement provides for.

supporting the tape in, a zigzag manner at turning points which are spaced apart, while the tape is being held under tension to prevent any accidental movements which would cause one flight of the tape to contact with another flight;

and by having the successive twists between supporting points, the tape always encounters the rollers which provide these supporting points at its carrier side, and the wax face is protected against contact throughout.

The tension rollers and the sound tape extending outside enclosed by adapted to a casting 20 surrounding a chamber the sound-recording apparatus are.

be heated by; a heater 2| supplied with a heating medium through the connections 22, the heat of which brings the wax composition of the sound tape to a temperature at which the stylus 3 effects the best cutting, and maintains the wax composition at this temperature.

The invention is not limited to the constructional examples described and illustrated, but numerous modifications may be made in the installation without departing from the invention. Thus, for example, in an installation as shown in Figure 2, it is not essential that all the rollers disposed outside the recording apparatus, over which the sound tape is passed, should be constructed as tension rollers. It is sufficient for one or a few of these rollers to be tension rollers.

I claim:

The method of recording sound upon a long endless tape having a carrier backing coated at one face with wax by cutting a sound track in the wax coating, which comprises supporting the major portion of, the endless tape in the form of loops passing in zigzag fashion about spaced turning points, said tape being twisted between consecutive turning points through 180 degrees about its longitudinal axis so that only the carrier backing contacts the supports and the wax coating is protected against contact, and maintaining the tape substantially throughout its length at a predetermined temperature for the optimum condition of the wax for the zigzag and twisting movement of the tape and for cutting the sound track, and during the passage of the tape from the cutting point through its zigzag and twisted course and back to the cutting point.

HUGO WESTERKAMP. 

